Field of the Invention
The present invention relates to an image stabilization apparatus configured to obtain a high-resolution image using a plurality of actuation means such as a variable angle prism or a shift lens for changing an imaging position with respect to an imaging plane and a method of controlling the same.
Description of the Related Art
In an image captured by an image capturing apparatus such as a digital camera, an object image sometimes blurs when, for example, the hand of a user holding the camera body swings at the time of image capturing to cause a so-called camera shake. The digital camera has a function of correcting an object image blur that appears in a captured image owing to vibrations acting on the camera body. Conventionally, optical image stabilization processing and electronic image stabilization processing have been known as a means for correcting such an image blur. This means is implemented by canceling the image blur by these processing operations.
In optical image stabilization processing, a vibration acting on the camera body is detected by an angular velocity sensor or the like, and an image stabilization lens provided inside an imaging optical system which forms an object image based on this detection result is moved to change the optical axis direction of the imaging optical system. Accordingly, in optical image stabilization processing, an image formed on the light receiving surface of an image sensor is moved to correct the image blur. In electronic image stabilization processing, image processing is performed on the captured image to pseudo-correct an image blur.
The image stabilization apparatus of the conventional image capturing apparatus has the following two problems in achieving a sufficient shake correction effect when driving a correction optical system. The problems are a delay in the traceability of a driving unit with respect to a target driving amount and the narrowness of a shake correction range.
To solve these problems, Japanese Patent Laid-Open No. 2002-250952 has proposed a method in which two shake correction optical systems are provided to switch lenses to be driven when a focal length is on the telephoto side or on the wide-angle side.
Japanese Patent Laid-Open No. 2002-250952 has only described that the focal length information of an image capturing apparatus is obtained and use of one of the two shake correction optical systems is selected depending on whether the focal length is larger than a predetermined value. However, Japanese Patent Laid-Open No. 2002-250952 has not described a measure for discontinuity in driving of a shake correction lens such as an actually problematic abrupt change in the field of view of a shot image that occurs at the time of changing the shake correction optical systems.